Role of macrolayer evaporation in pool boiling at high heat flux

Analytical expressions for macrolayer thickness and the rate of heat transfer through a macrolayer in a high heat flux region near the critical value were reported in previous papers by the authors. The results of an experimental investigation into the liquid macrolayer formation are being reported in this paper. The initial thickness of this liquid layer formed between the heated surface and the vapour mass and the frequency of the vapour mass as a function of impressed heat flux have been measured. Using these data, the contribution of macrolayer evaporation to the heat flow from heated surface to bulk has been estimated. Experimental results of macrolayer thickness and frequency of vapour mass have been found to compare well with analytically predicted values. Contribution of heat conduction through the macrolayer has also been found to account for a considerable portion of wall heat flux.